In a sports competition, it is often necessary to use several devices to detect and store the measured time of a race, in order to ensure the serviceability of the measuring system. These devices must also ensure good measurement accuracy and measurement security to be able to form an automated measuring system. The devices used in this type of measuring system are, for example, contact strips, cameras, photoelectric cells and transponders.
It should also be noted that if the time difference between athletes is less than the accuracy of the transponders used, a manual checking operation must also be used. The conventional measuring system cannot therefore be entirely automated, which is a drawback.
U.S. Pat. No. 5,511,045 describes an apparatus and a system for timing moving objects, such as sports persons, during a sports competition. The measuring system performs a time measurement for each competitor from the start line to the finish line, and a measurement of split or intermediate times. One or more transmitters/receivers are disposed at points on the race track to capture information from the personalised transponders worn by the competitors. Each transponder can be incorporated in a watch worn on the wrist of each competitor. When each transponder detects a detection signal from a transmitter, the identification code is transmitted by the transponder to be captured by a receiver when the competitor crosses a line. This allows the receiver to determine the time for each competitor based on the received identification code. No other information is transmitted by each transponder for exact determination of the time that an intermediate or finish line is crossed. This constitutes a drawback of this measurement system.
EP Patent No 1 447 681 B1, which discloses a system for determination of a crossing time, may also be cited. The determination system includes a magnetic field signal generating arrangement, personalised transponders each worn by a moving object, such as a competitor, and a receiver of signals received from transponders. Each transponder measures several intensities of a magnetic field transmitted on each line of passage by the signal generating arrangement. Each transponder transmits these intensities and associated times so as to allow the receiver to determine a crossing time. However, no absolute time reference is defined to allow a processing means of the receiver to reconstruct the magnetic field pattern and thus to accurately determine the actual crossing time of each transponder. Further, the determined crossing time of each transponder is determined on the basis of magnetic field intensity samples taken at random times, which constitutes an additional difficulty for accurately determining the crossing time. These are several drawbacks of this system for determination of a crossing time.
EP Patent Application No 2 747 036 A1 describes a method and a system for the measurement of a time in a sports competition with at least one personalised transponder module placed on the competitor. Said module can be activated either at the start of the race, or at intermediate positions on the race course or track or at the finish line. A variation in motion is detected by a motion sensor of said module at at least one crossing point. The motion measurements can be transmitted from the module to a decoder unit to check a crossing time. However, it is difficult to accurately measure the crossing time of one or more activated modules at a defined crossing point, which constitutes a drawback.